Alkylation of Partially Protected Xylofuranoses and Tetritols with (2,2,3,3,4,4,5,5,6,6,7,7,7-Tridecafluoroheptyl)oxirane and the Stability of Protecting Acetal Groups Towards Lewis Acid-Type Catalyst

Autor:	Karel Kefurt, Z. Kefurtova, Sarka Bambasova, Kateřina Buchalová, Barbora Vymětalíková, Oldřich Paleta, Jitka Moravcová, Jan Staněk
Rok vydání:	2001
Předmět:	chemistry.chemical_compound Polymerization Chemistry Acetal General Chemistry Lewis acids and bases Alkylation Medicinal chemistry Boron trifluoride Catalysis Lewis acid catalysis
Zdroj:	Collection of Czechoslovak Chemical Communications. 66:1665-1681
ISSN:	1212-6950 0010-0765
Popis:	1,2-O-Isopropylidene-3-O-methyl-α-D-xylofuranose (2), 1,2-O-isopropylidene-α-D-xylofuranose (3), 2,4-O-ethylidene-D-erythritol (4) and 1,3-O-ethylidene-D-threitol (5) were alkylated with racemic (2,2,3,3,4,4,5,5,6,6,7,7,7-tridecafluoroheptyl)oxirane (1) using boron trifluoride diethyl etherate as a catalyst. The desired mono- or disubstituted polyfluoroalkyl derivatives 6-11 were isolated only in low to medium yields. The fluoroalkylation was accompanied with disproportional distributions of the protecting acetal/ketal groups and polymerization of saccharides. Therefore the stability of 3, 4, 5, 5-O-acetyl-1,2-O-isopropylidene-α-D-xylofuranose (14) and 1,2-O-isopropylidene-α-D-glucofuranose (15) in the presence of a catalytic amount of boron trifluoride diethyl etherate was investigated in various solvents. A mechanism explaining the effect of the catalyst has been proposed.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::1d6520bfdd636eb0e4a08e06a451cab5 https://doi.org/10.1135/cccc20011665 Zobrazit plný text záznamu